This invention relates to tracheostomy tube assemblies.
Tracheostomy tubes are used to provide ventilation, or to administer anaesthetic gas to a patient's trachea, via an opening, or stoma, in the patient's throat. The tube is bent at about 90 or 110 degrees and its forward end can be provided with an inflatable cuff that seals the outside of the tube with the patient's trachea. The rear end of the tube emerges through the opening in the patient's throat and has a flange which is used to secure the tube in position by means of a collar passed around the neck, or an adhesive tape. The rear end of the tube is either left open to allow the patient to breathe freely through the tube, or is connected to a ventilating machine to enable forced ventilation.
Because the build of patients varies one from the other, the flange by which the tube is secured is not usually located in the ideal position. For a patient with a thick layer of tissue between his trachea and the surface of his neck, the length of the standard tube is such that the cuff may not be located correctly in the trachea, thereby leading to a poor seal. For patients with a thinner layer of tissue, the flange may be spaced by a gap from the neck surface. With such a patient, if the flange is pushed against the neck, the forward end of the tube may contact the trachea wall, leading to abrasion and possible stenosis. To reduce this, the flange may be left spaced from the neck and gauze padding can be placed between the flange and the patient's neck. This can, however, provide a site for infection.
Various arrangements have been proposed to provide the tracheostomy tube with a flange that can be moved along the tube, making it adjustable to the best position for each patient. These arrangements, however, are not generally satisfactory for several reasons. Because the surface of the tube is smooth and can be wet, it is difficult to produce a flange that can be locked securely relative to the tube, and that can also be displaced freely for positioning purposes. Some adjustable flanges have a tendency to twist the tube when they are locked or unlocked and can be uncomfortable to the patient.